Parasites4 Flashcards
Demodex spp.
- “Follicular Mange Mite”
* Adult is 0.25 mm long, cigar-shaped, found in hair follicles and sebaceous glands
Importance, Diagnosis,Control Sarcoptesscabiei
- Importance- Severe dermatitis
- Diagnosis- Deep skin scraping
- Control- Apply miticide, clip hair and bathe
Sarcoptesscabiei
- “Mange Mite”
* Adult 0.3-0.5 mm, burrows tunnels into skin
Importance, Diagnosis, Control of Demodex
- Importance-Severe dermatitis
- Diagnosis- Deep skin scraping
- Control- Treat w/ topical or systemic miticide
Trichodectescanis
- “Dog biting louse”
* Adult 2-4 mm, egg 0.5-1 mm
Importance, Diagnosis, Control Trichodectescanis
- Importance- Causes irritation and dermatitis, rough hair coat, intermediate host for Dipylidium caninum
- Diagnosis- Examine hair coat for adults, nymphs, eggs
- Control- Apply topical insecticide
Linognathussetosus and Importance, Diagnosis, Control
- “Dog sucking louse”
- Adult 2-3 mm, egg 0.5-1 mm
- Importance- Irritation and dermatitis, rough hair coat, anemia
- Diagnosis- Examine hair coat for adults, nymphs, or eggs
- Control- Apply topical insecticide
Rhipicephalussanguineus and Importance, Diagnosis, Control
- “Brown dog tick”
- Adult 1 cm
- Importance- Irritation, anemia, tick paralysis
- Diagnosis- Finding tick on skin/ hair coat
- Control- Treat host w/ topical antiparasitic
Lyme Disease
- Bacterial infection caused by - Borrelia burgdorferi
- Tick vector
- Bacteria is maintained in wildlife reservoirs that cause no apparent clinical disease in infected animals
Syndrome of Lyme Disease
o Humans: erythema migrans- red, circular papule with “target” appearance (may have more than one)
Fatigue, fever, headache, muscle and joint pain
Arthritis, CNS and cardiac problems may develop without treatment
o Wild animals - subclinical
o Domestic animals - fever, anorexia, swollen lymph nodes, lameness, fatigue
Incubation period, Mode of transmission, Diagnosis of Lyme disease
- Incubation period:3-32 days for appearance of papule
- Mode of transmission- Through bite of an infected Ixodes spp. Tick
- Diagnosis- History, syndrome, serology, culture of blood or tissue biopsy
Treatment of Lyme Disease
Antibiotics
o Patients treated with antibiotics in the early stages of the infection usually recover rapidly and completely. A few patients, particularly those diagnosed with later stages of disease, may have persistent or recurrent symptoms.
Control and prevention of Lyme Disease
o Avoid tick bites
o Control ticks around your house
o Manage wildlife populations (deer, squirrel)
o Seek medical help after tick bites
Rocky Mountain Spotted Fever
• Tick transmitted disease caused by: Rickettsia rickettsii
• Ticks serve as vector and reservoir of infectionàTransovarial transmission
o Transtadial transmission
• Disease most prevalent in south Atlantic states and Midwest
Syndrome of Rocky Mountain Spotted Fever
o Human– fever, myalgia, headache, chills
skin rash on extremities
capillary damage, liver disease
o Wild animals– subclinical
o Domestic animals– fever, anorexia, swollen lymph nodes
– dyspnea, abdominal pain, edema of face and extremities
conjunctival bleeding and retina damage
Mode of transmission of Rocky Mountain Spotted Fever
o Through the bite of an infected tick
• Dermacentorvariabilis
• Dermacentorandersoni
o Contact of skin or mucous membranes w/ tick body fluids when removing it
Control and prevention of Rocky Mountain Spotted Fever
o Wear protective clothing when entering tick habitat
o Use tick repellents
o Check yourself and your dog for ticks and remove them carefully
o Clear brush away from residential areas
Incubation,Diagnosis, Treatment of Rocky Mountain Spotted Fever
• Incubation period is 3 to 14 days • Diagnosis o History of tick bite, rash, and fever o Serology • Treatment- Antibiotics
Cuterebra spp
- “Rabbit bot fly” “Rodent botfly”
- Adult is a fly, larval stage sometimes infects domestic animals
- Importance- Irritation, tissue damage
- Diagnosis- Presence of subcutaneous lump w/ breathing hole for larva
- Control- Extraction of larva
Gastrophilus spp.
- “Bot” “Bot fly”
- Adult is a fly, larva is brown and 2 cm, eggs are yellow
- Importance- Cause stomach ulcers, “worry factor”
- Diagnosis- Eggs on hair of legs and face
- Control- Deworm infected horses
Siphona spp.
- “Horn fly”
- Adult fly is 4-5 mm, dark-colored
- Importance- Loss of production due to irritation
- Diagnosis- See adult fly feeding on cow
- Control Apply topical insecticide to animal and premises
Tabanus spp.
- “Horse fly”
- Adult is up to 3 cm
- Importance- Painful biter, “worry factor”
- Diagnosis- See adult fly bite animal
Hypodermalineatum
- “Cattle bot fly” “Cattle grub” “Warble fly”
- Adult is 3cm
- Importance- “worry factor”, tissue damage
- Diagnosis- Cyst-like swelling w/ breathing hole (warble)
- Control- Apply topical insecticide
Blow Fly
- “Sheep bottle fly” “Sheep blowfly”
- Adult is a fly, larva is a maggot/grub 1.5 cm
- Importance- Causes myiasis
- Diagnosis- Larva in open wound
- Control- Clean wound, apply insecticide
Dermatophytosis
• Fungal infection affecting keratinized tissueà skin, hair, nails
• Causative fungi
o Microsporum spp.
o Trichophyton spp.
• Reservoirs of infection include animals, humans, and the soil
Clinical signs of Microsporumcanis
- round lesions of alopecia, scaling, crusting
- face, ears, and extremities most often involved
- some infected animals may not show a lesion
most commonly involved in animal to human transmission of ringworm
Microsporumcanis
Diagnosis of Microsporumcanis
o microscopic examination of skin scraping
o fungal culture
o Wood’s lamp examination, infected tissue fluoresces yellow-green color
Three forms of dermatophites
- ringed lesions
- subclinical
- kerion- raised tumor like growth/lesion
Treatment of Microsporumcanis
- Spot treatment– clip and clean around lesion, apply topical antifungal
- Whole body treatment– bathe w/ antifungal shampoo and/or administer oral antifungal medication
Human symptoms of Microsporumcanis
o Spreading ring-shaped lesions on the head or body
o periphery is reddish w/ vesicle, pustule formation
o skin surface may be dry and scaly or moist and crusted
o healing begins at center of lesion
Fungal culture
Sabauraud’s dextrose agar
Low pH to prevent a variety of organisms from growing in it. Promote the growth of fungus.
Starts off as amber. Indicator- changes to red. Look at growth
Methods of diagnosising ringworm
- Microscopic exam of skin scrape
- Fungal culture
- Wood’s lamp examination
Human symptoms of dermatophytosis
o Spreading ring-shaped lesions on the head or body
o periphery is reddish w/ vesicle, pustule formation
o skin surface may be dry and scaly or moist and crusted
o healing begins at center of lesion
Mode of transmission of dermatophytosis
Direct contact w/ infected skin or hair, or contaminated inanimate objects
Control and prevention of dermatophytosis
- Treat infected people to prevent spread of infection to others
- Treat infected animals to prevent transmission
- Clean and disinfect inanimate objects in contact w/ infected animals
